Foot trainer with adjustable rotation and friction means



March 12, 1968 M. P; SERTICH 3,372,930

FOOT TRAINER WITH ADJUSTABLE ROTATION AND FRICTION MEANS Filed May 5, 195 2 Sheets-Sheet 1 INVENTOR MICHAEL P. SERTICH BY S mes 82/720283ATTORNEY March 12, 1968 M. P. SERTICH 3,372,930 v FOOT TRAINER WITHADJUSTABLE ROTATION AND FRICTION MEANS Filed May 5, 1965 2 Sheets-Sheet2 INVENT OR MICHAEL P. SERTICH BY Semmes Serums;

ATTORNEY United States Patent 3,372,930 FOOT TRAINER WITH ADJUSTABLEROTATION AND FRICTION MEANS Michael P. Serfich, 200 Henry Grady Bldg.,Atlanta, Ga. 30303 Filed May 5, 1965, Ser. No. 453,286 6 Claims. (Cl.273- 26) ABSTRACT OF THE DISCLOSURE The invention is a trainer forsportsmen which is designed to restrict, while guiding, the rotationalmovement This invention relates generally to the field of sports, andmore particularly to those sports in which the rear foot action andpivot is essential for proper body movement and coordination. Forexample, in baseball, it is important for the hitter to pivot and pushoff the ball of the rear foot when batting, for complete utilization ofthe body and, consequently, proper hitting technique and form.

Proper action of the rear pivotal foot gives better body balance,necessary hip pivot, the desired shorter and straight front foot stride,and level shoulders and hips for a level swing and head restrained fromexcessive movement, so that the batters eyes can better follow the ball.The desired body movement and coordination will result from properpivoting of the rear foot, thus giving better timing and maximum power.

The common fault with a majority of hitters, especially beginners, ishitting off the front foot, thereby preventing the back foot frompivoting properly. This results in lunging forward and otf timing,particularly when the speed of pitched balls changes. Otf balance, whichusually causes overstriding and turning of the head, results in thehitters inability to keep his eyes on the ball.

Hitters are made, not born, through proper instructions and practice.Good hitters continue to practice hitting form to retain or improvetiming and coordination, since proper hitting techniques come as aresult of the proper pivoted action of the rear foot.

It is thus necessary if a player is to become expertise in such sports,to be taught the proper use of the rear foot, which in turn, leads tothe proper desired hitting form.

This invention is therefore concerned with an apparatus for teachingproper rear foot pivot primarily for baseball as well as other varioussports such as softball, golf, tennis or any sport where the rear footpivot action is essential or desired. This will become apparent from thefollowing specification and attached drawings which describe theinvention in terms of a baseball form training apparatus.

The object of this invention is to provide an apparatus to teach properplayer form for sports. This device can i be used indoors or outdoors,with or without a platform.

Another object of this invention is to describe a device 3,372,939Patented Mar. 12, 1968 which may readily be used by individuals, as wellas large groups of players, such as by a professional club, or byamateur groups such as Little League, etc., as part of their ordinarytraining.

My invention is illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of a preferred form of this invention,illustrating the back foot stance training device;

FIG. 2 is a plan view of said back foot stance training device, lookingfrom the top thereof;

FIG. 3 is a cross-sectional side view of the back foot stance trainingdevice, taken along the sectional lines 3-3 of FIG. 2;

FIG. 4 is an enlarged cross-section view of the tension adjustmentmeans, taken along the sectional lines 4-4 of FIG. 2;

FIG. 5 is an enlarged perspective view of the angle adjustment meansused to vary the maximum angular displacement of the training devicewith the upper plate deleted to clarify the operation thereof;

FIG. 6 is a plan view of a modification of the foot support,illustrating a heavy textured matting surface that may be utilized tosupport spikes on a shoe to simulate actual playing conditions;

FIG. 7 is a plan view of a modified form of this invention showing thatholes for spikes may be provided on the foot support section of thetraining device;

FIG. 1 illustrates a preferred form of the invention for use by abaseball player. This assembly comprises two sections, base supportsection 12 and back foot support 14 which is rotatable on base supportsection 12.

The rotatable relationship between base support section 12 and back footsupport 14 is more clearly illustrated in FIG. 3. FIG. 3 is across-sectional view of the entire housing assembly, and shows that thebase support section 12 is comprised of an upper plate 16 and a lowerplate 18, which are preferably made of steel. As further illustrated inFIG. 3, plate 18 has an upward right angle flange section 19 and anoutward right angle flange section 20 extending therefrom. Extendedright angle flange section 22 of plate 16 thereby securely fits aroundthe entire periphery of plate 18. This secure fit seals the innersection as defined by the lower plate 18 and upper plate 16 and theirassociated fitted flanges and keeps dirt, or whatever surface basesupport section 12 is buried in from getting into the inner section.

As illustrated further in FIG. 3, the assembly is buried in the groundto a level at which the top of plate 16 is at the level of groundsurface 26. Thus, the relative positions of the feet in normal play aresimulated by this apparatus. Spikes 28 are attached, either throughwelding or other mechanically equivalent means, to the flange section 20of lower plate 18 at intervals. Thus, there are four spikes 28. Thesespikes extend into the earth, and securely hold the base support section12 so that it does not change its position when being used.

As further illustrated in FIG. 3, plates 16 and 18 define radialindentations 32 and 34 which are fitted oppositely from each other, thatsupport a series of ball bearings 36 evenly spaced throughout the radialdistance of the indentations. A rim-plate 38 is provided with cutouts 40to fit around ball bearings 36 and hold them securely in place betweenplates 16 and 18. Center shaft 50 supports the assembly 10, and isfitted into bore 52 of back foot support 14, which is rigidly fixed byscrews or any equivalent mechanical means to upper plate 16 and rotatestherewith.

FIGS. 1 and 2 illustrate the foot support means 14 which is used tosupport the back foot as the device is being used. The back foot support14 consists of a base 60 which is preferably cut out in the form of anenlarged shape of a human foot. The base 60 is symmetrical along itslongitudinal axis so as to accommodate both left and right feet,depending upon the batter. Belt 62 is used to keep the'toe part of thefoot in the desired secure position. As illustrated in FIG. 1, belt 62is adjustable on either its right or left side, to accommodate a left orright handed batter, and is made of an elastic material which gives wayslightly as the position of the foot changes as the device is beingused.

Belt buckle adjusting means 6 and 64 are secured to either side of base60 and provide for adjustment of the belt 62 by either a left or righthanded player. It consists of base members 65 and 65 having pivotallysup ported cylindrical elements 68 and 68', respectively, around whichbelt 62 is wound inwardly and then outwardly. This is more fullyillustrated in FIG. 3. The bottom portion of buckle adjusting means 64and 64 which are located directly below pivotally supported elements 68and 68' are jagged so that when the belt is set to the desired position,it will not slip back. By slightly lifting the belt 62 away from thejagged buckle edges, it may slide around rotating elements 68 and 68' toset itself to a new position as desired.

Complementary guide means 66 and 66' are mounted on base 60 to guide andposition the heel of the foot thereon. As shown in FIGURES 1, 2 and 7,guide means 66 and 66 comprise two coacting L-shaped members thatdiverge from the back portion to the front portion of base 60, andtherefore function to accommodate different foot sizes.

As illustrated in FIGS. 2 and 5, back foot support 14 is adjustablyrotatable in relation to base support section 12. More particularly,since base 60 is fixed to top plate 16, it is rotatable with respect tobottom plate 18. The degree of free rotation is fixed by stops 70 and'70, which coact with bolts 72 and 72', respectively, and which protrudefrom the bottom plate 18 (FIG. FIGURE 5 thus shows that stop 70protrudes from bottom plate 18, to

coact with adjustably positionable bolt 72 to fix the degree ofclockwise rotation. It is mounted to the right of center of assembly(FIGURE 3). A similar arrangement (not shown) of stop 70 and bolt 72 tofix the degree of counter-clockwise rotation is mounted tothe left ofcenter of assembly 10. In this regard, the arrangement comprising stop70 and bolt 72' has not been illustrated to clarify the drawings in viewof the similar structure and function'of corresponding elementsidentified by the same identification numbers. However, the location ofbolt 72 to the left'of center of assembly 10 is shown in FIGURE 1. Thus,components identified by the prime designation in conjunction with anidentification number are structurally and functionally similar to thecorresponding elements identified by the same identification number; forexample, stops 70 and 70' are structurally and functionally similar.

Upper plate 16 is not shown in FIGURE 5, in order to clarify theoperation of stop 70 and bolt 72. Thus, the operation of the angularadjusted means is shown in FIGURE 5 with relation to stop 70, bolt 72,slot 74, guide plates 76 and 78, and groove 80. A similar arrangementcomprising the corresponding elements identified by the sameidentification numbers and having the prime designation (stop 70, 76 and78 and groove 80') is provided to the left of center of the assembly toadjust the degree of counterclockwise rotation. Bolt 72 and 72' aremounted through base 60 of the back foot support 14, as shown in F1"-URESS and 5 and extend through the top plate 16 bolt 72, slot 74, guideplates 4 through slots 74 and 74' respectively. The position of bolts 72and 72' in slots 74 and 74 are adjustable. This adjustability isobtained by providing guide plate sets 76 and 78, and 76 and 78, onopposite sides of base of the back foot support 14, to hold bolts 72 and72 respectively in secure position.

Guide plates 78 and 78 contain a bore which is threaded to fit thethreaded portions of bolts '72 and 72' respectively. When it is desiredto change the amount which the back foot support section 14 may befreely rotated, the bolt 72 or 72 is merely loosened from guide plate 78or 78', and moved to the desired position along groove 80 or 80,respectively. When the desired position which will give the desiredangular displacement is obtained, it is again locked into place. Asnoted from FIG. 3, bolts 72 and 72' are wing-nut type bolts.

FIGS. 2 and 5 illustrate the tension adjustment means which is anotherimportant part of this invention. The tension adjustment means comprisesa braking type material 9t) affixed to the bottom plate 18. Asillustrated in FIG. 2, the braking material 9?: extends for a radialdistance of because the maximum displacement of the back foot supportsection 14 is 45 in either direction, or a total of 90. A correspondingbraking material 92 in a circular form is attached to shaft 93. Shaft 93is threaded to fit the threads of plate 16 through which it extends, andis rotated by knob 96. Knob 96 selects the desired tension value, which,respectively, is indicated along the periphery of indicator 94 asindicated in FIG. 2. Thus, for example, if a strong player is to use thedevice, the tension will be set very high because he will have a lot offorce behind him. On the other hand, if for example, a Little Leagueplayer is to use the device, the tension adjustment means would beloosened to offset his relatively weak power. The purpose of the tensionadjustment means is to simulate actual playing conditions, in which theground provides a friction force which counteracts the body force as thefoot is rotated.

FIG. 6 represents a modification of this invention in which the backfoot support section 14 is deleted. This modified form of my inventionis smaller than the device illustrated in FIG. 1, and, as illustrated,accommodates only the front or toe portion of the players foot. Aplastic mat-like material 100 is affixed to plate 16. This materialclosely simulates the resistance which the surface of the ground, moreparticularly a grass playing field, exerts on a player wearing spikes.The purpose of this modification is that a player may use the device,without removing his spiked shoes, and simulate actual playingconditions. The material is of such a type that it resumes its originalshape after the spikes are removed after use by a player. The rest ofthe device is as explained heretofore, in that angular adjustment means102 and 102' and tension adjustment means 104 comprise part of thismodified form of my invention. It will be apparent from reference toFIGS. 1, 2, 3, 6 and 7 that the same concept of FIG. 6 might be appliedto the species of FIGS. 1, 3 and 7. For example, the turntable plateshown in FIG. 6 may be sufficiently large to accommodate the entire footof the player.

FIG. 7 represents a further modification of this invention in which thebase 60 additionally comprises holes and/or indentations to fit thespikes of a baseball players shoes. Thus, the players back foot will befirmly held in position, as he practices batting. The indentations orholes are exaggerated, so that they may fit different size shoes.

The preferred form of my invention, as heretofore described, works inthe following way.

The baseball player desiring to use the pivot training device topractice batting, and more particularly to learn the best position ofthe feet during the batting swing, will merely place his foot on theback foot support section 14. The foot he places on said support sectionwill depend on whether he is a left or right-handed batter. Belt 62 willthen be adjusted to provide the proper toe support for the particularsize foot. The adjustable angular displacement means will be adjusted togive the desired angular displacement, a range of up to 45 in eitherdirection. The tension adjusting control 96 will then be adjusted tovary the friction between brake linings 92 and 90 and thus the frictionand/or tension exerted by said brake linings. Indicator 94, for example,may be scaled in terms of pounds of the individual player. The moreweight and/ or power of the player, the greater tension must be exertedby the linings 92 and 90 to counteract the force of the player.

FIG. 2 indicates the initial starting position. Assuming that the playeris a right-handed batter, he will swing and move his foot so that theback foot support section 14 will move counter-clockwise. As the playersfoot moves, during the period of this swing, his heel will be able to beraised from the support means because nothing is keeping it down. Theraising of the heel of the foot towards the completion of the swing isnecessary to obtain power and follow through. However, the belt 62 willkeep the toe in proper position, i.e. on the surface of the back footsupport.

The advantage of this invention is that it may be used by a wide groupof people to simulate actual playing conditions. It is completelyvariable in that it accommodates players with different foot sizes, aswell as different ability as regards power. Furthermore, the player mayadjust the angular displacement of his swing, as regards back footdisplacement, to determine just what angular displacement gives him themost powerful and accurate swing.

Whereas the aforementioned description has described the species ofFIGS. 1, 2, 3, 6 and 7, it will be apparent to those skilled in the artthat the turntables of the respective species may comprise spikeengaging patterns in lieu of the mat shown in FIG. 6 or of the shoeengaging element 14 of FIG. 1. In the FIG. 6 species a pattern havingplural depressions corresponding to the players toe spikes could beemployed; whereas in the other species a pattern having pluraldepressions corresponding to the spike projections of the entire footmight be employed.

Although I have described my invention for particular use by a baseballplayer, it may also be used in other sports, for example, golf. Thus,when taking a swing at a golf ball my invention may be utilized toobtain correct rear foot pivot action for proper body movement andcoordination. That is, it is designed for use in sports where theposition of the rear foot changes angularly when playing, for example,when taking a swing at a ball. The adjustable angular displacement andtension enable a player to determine the pivot action which will givehim optimum power and coordination. After form ing the proper hittinghabits through continued use of this invention, he will then be able totranslate them to the actual playing field.

Having described my invention, I claim the following:

1. A training device to teach the proper pivot and action of the backfoot when hitting a baseball which comprises:

(A) an housing consisting of a fixed lower plate and an upper plate inrotatable relationship with said fixed lower plate;

(B) means to mount said housing securely in a dug-out portion of theground with the top surface of the upper plate being at ground level;

(Al) foot support means mounted to said upper plate and designed toaccommodate the left foot or a right foot, depending upon the player;

(Ala) guide means mounted on said foot support means to guide theposition of a players heel on said foot support means;

(Alb) toe securing means to secure the toe portion of the foot of theplayer to said foot support means, said toe securing means beingadjustable to accomlmodate diiferent foot sizes;

(C) angular adjustment means to vary the angle of rotation of said topplate and its afiixed foot support means with respect to said lowerplate, in either direction, the range of said angular displacement beingup to 45 in either the clockwise or counterclockwise direction;

(D) tension adjustment means, to vary the friction force between saidupper and lower plates, according to the power of the individual player.

2. The training device of claim 1 wherein said tension adjustment meanscomprises a braking lining afiixed to both said upper plate and saidlower plate, which contact each other as the upper plate is rotated,said brake lining attached to said upper plate being adjustable withrespect to said lower plate brake lining, to thereby vary the frictionbetween the two, and thus vary the force required to rotate said upperplate with respect to said lower plate.

3. The training device of claim 1, wherein said angular adjustment meanscomprises a stop attached to said lower plate, a groove defined by saidfoot support means and said upper plate, a bolt adjustably positionedwithin said groove so as to hit said stop on said lower plate atdifferent degrees of confinement according to the setting of said boltwithin said groove.

4. A training device to teach the proper pivot and action of the backfoot when hitting a baseball which comprises:

(A) an housing consisting of a fixed lower plate and an upper plate inrotatable relationship with said fixed lower plate;

(B) means to mount said housing securely in a dug-out portion of theground with the top surface of the upper plate being at ground level;

(C) a matted plastic material afiixed to said upper plate which resumesits original shape after spikes are removed from it, to accommodatespikes on sport shoes to simulate actual playing conditions;

(D) angular adjustment means to vary the angle of rotation of said topplate and its afiixed back foot support means with respect to said lowerplate, in either direction, the range of said angular displacement beingbetween 40 and 45 in either the clockwise or counterclockwise direction;

(E) tension adjustment means, to vary the friction force between saidupper and lower plates, according to the weight and desired speed androtation of the individual.

5. A pivot position trainer prising;

(A) an housing, including a lower section and an upper section, saidlower section being in fixed relationship to said upper section and saidupper section being in rotatable relation with said lower section, saidupper section comprising:

(1) a plate upon which is attached:

(1a) a foot support, said foot support including:

(lal) means to guide and position the heel of a foot mounted on saidback foot support;

(1a2) means to support the toe of the foot in secure position on saidback foot means;

(2) means to adjust the angular displacement of said upper sectionrelative to said lower section; (3) tension means disposed between therespective sections to vary the tension as said upper section is rotatedby the foot of the user, said tension means being adjustable by varyingthe force of friction between two brake linings, one of which isconnected to said upper section and for use in sports, com- 7 8 theother of which is connected to said lower References Cited sectlon-UNITED STATES PATENTS 6. The device of claim 5, wherein said back footsupport comprises a symmetrical foot shape member, and 2'004671 6/1935 i128-252 wherein said guide means for said heel comprises two 5 21896132/1940 f i 273' 188 L-shaped members which are divergent from the backOf 2849237 8/1958 slmlthls 272 57 said foot shaped member towards thefront of said foot- FOREIGN PATENTS shaped member to accommodatedifferent foot sizes, and 1,291,700 3/1962 France wherein said toesupport means comprises an elastic type matenal- 10 RICHARD C. PINKHAM,Primary Examiner.

